realtek: pcs: drop PCS creation without SerDes ref

Since the beginning, the PCS driver had the ability to call its
rtpcs_create without a reference to a valid PCS node. A comment in the
code mentions that this is done for RTL838X and its built-in octa-PHY
which is connected directly instead of via a SerDes. Further
explanations are not provided.

Drop this ability and make the rtpcs_create call in the dsa driver
conditional. As the built-in PHY of RTL838X isn't attached to a SerDes,
there is no obvious point of having the PCS driver in that chain. The
ports are marked as internal and have no pcs-handle, thus no phylink_pcs
instance should be created.

Signed-off-by: Jonas Jelonek <jelonek.jonas@gmail.com>
Link: https://github.com/openwrt/openwrt/pull/21146
Signed-off-by: Robert Marko <robimarko@gmail.com>

2 files changed, 15 insertions, 25 deletions

diff --git a/target/linux/realtek/files-6.12/drivers/net/dsa/rtl83xx/common.c b/target/linux/realtek/files-6.12/drivers/net/dsa/rtl83xx/common.c
index 85818391b5..787ceda834 100644
--- a/target/linux/realtek/files-6.12/drivers/net/dsa/rtl83xx/common.c
+++ b/target/linux/realtek/files-6.12/drivers/net/dsa/rtl83xx/common.c
@@ -331,12 +331,14 @@ static int __init rtl83xx_mdio_probe(struct rtl838x_switch_priv *priv)
 			continue;
 		}
 
-		priv->pcs[pn] = rtpcs_create(priv->dev, pcs_node, pn);
-		if (IS_ERR(priv->pcs[pn])) {
-			dev_err(priv->dev, "port %u failed to create PCS instance: %ld\n",
-				pn, PTR_ERR(priv->pcs[pn]));
-			priv->pcs[pn] = NULL;
-			continue;
+		if (pcs_node) {
+			priv->pcs[pn] = rtpcs_create(priv->dev, pcs_node, pn);
+			if (IS_ERR(priv->pcs[pn])) {
+				dev_err(priv->dev, "port %u failed to create PCS instance: %ld\n",
+					pn, PTR_ERR(priv->pcs[pn]));
+				priv->pcs[pn] = NULL;
+				continue;
+			}
 		}
 
 		if (of_get_phy_mode(dn, &interface))
diff --git a/target/linux/realtek/files-6.12/drivers/net/pcs/pcs-rtl-otto.c b/target/linux/realtek/files-6.12/drivers/net/pcs/pcs-rtl-otto.c
index e41c89e713..8368870b62 100644
--- a/target/linux/realtek/files-6.12/drivers/net/pcs/pcs-rtl-otto.c
+++ b/target/linux/realtek/files-6.12/drivers/net/pcs/pcs-rtl-otto.c
@@ -2930,26 +2930,12 @@ struct phylink_pcs *rtpcs_create(struct device *dev, struct device_node *np, int
 	struct device_node *pcs_np;
 	struct rtpcs_ctrl *ctrl;
 	struct rtpcs_link *link;
-	int sds;
-
-	/*
-	 * RTL838x devices have a built-in octa port RTL8218B PHY that is not attached via
-	 * a SerDes. Allow to be called with an empty SerDes device node. In this case lookup
-	 * the parent/driver node directly.
-	 */
-	if (np) {
-		if (!of_device_is_available(np))
-			return ERR_PTR(-ENODEV);
-
-		if (of_property_read_u32(np, "reg", &sds))
-			return ERR_PTR(-EINVAL);
+	u32 sds;
 
-		pcs_np = of_get_parent(np);
-	} else {
-		pcs_np = of_find_compatible_node(NULL, NULL, "realtek,otto-pcs");
-		sds = -1;
-	}
+	if (!np || !of_device_is_available(np))
+		return ERR_PTR(-ENODEV);
 
+	pcs_np = of_get_parent(np);
 	if (!pcs_np)
 		return ERR_PTR(-ENODEV);
 
@@ -2972,7 +2958,9 @@ struct phylink_pcs *rtpcs_create(struct device *dev, struct device_node *np, int
 	if (port < 0 || port > ctrl->cfg->cpu_port)
 		return ERR_PTR(-EINVAL);
 
-	if (sds !=  -1 && rtpcs_sds_read(ctrl, sds, 0, 0) < 0)
+	if (of_property_read_u32(np, "reg", &sds))
+		return ERR_PTR(-EINVAL);
+	if (rtpcs_sds_read(ctrl, sds, 0, 0) < 0)
 		return ERR_PTR(-EINVAL);
 
 	link = kzalloc(sizeof(*link), GFP_KERNEL);